Pressure-relief door for heating units



Dec. 30, 1952 AYERS 2,623,482

PRESSURE-RELIEF DOOR FOR HEATING UNITS Filed Jan. 25, 1951 I ,z I I I II I I JEKEHZUE IA/lLL/Al"! D. AYEQS Patented Dec. 30, 1952 UNITED STATESPATENT OFFICE PRESSUREsRELIEF DOOR FOR HEATING UNITS:

William P.v Ayers, L'ombard,]ll..

Applicatiamldznuamfid 19.51, SerialJNo'. 207,751

( Cl. fills-17.31).

This invention rel-ates to a heating; unit'- door construction and moreparticularly" is directed to a doordevice for furnaces; boilers, orthelike, which is so constructed as to automatically reli'eve' internalpressures developed therein, including explosions or the like.

In the usual constmction' of a furnace, boiler, orother heating unit, amanually operated door is provided through which to view the interior orto supply fuel thereto. Generally; these doors are of th swinging typeheld in a closed position by friction or by alatch arrangement.Quitefrequently; through improper firing or for other reasons, anexplosion of gases occurs. Such explosions force the furnace door to anopen-position thereby relievingthe-suddenly generated pressure. Unlessthe door is immediately closed, additional gases and even flames flowout through the open doorway; As a result, occupants of the building areendangered either by asphyxiation or by fire.

This invention is directed to theelimination of these dangers byproviding a door which swings open to relieve pressure and thereafterimmediately and automatically returns to aclosed position.

Briefly described; my invention consists of a covering shield to beapplied over the open doorway of a furance, boiler; or other heatingunit. Should a heating unit such as a gas; oil or other burner beinstalled, an opening therefor is provided through the shield. Anotheropening for a doorway is also provided. In the latter opening isinstalled a door constructed according to the principles ofthisinvention.

The door has an exterior opening coveringponti'on andan offsetcounter-weight. portion positioned within the heating unit. The offsetacts asafulcrum resting on the bottom ledge ofthe doorway. By locatingthe counter-weight portion below the covering portion and the fulcrum,the door is normally maintained in a closed position. A thrust resultingfrom gas or other pressure in the heating: unit against the coveringportion of the door either partially or completely overcomesthe weight.of the counter-weight portion thereby effecting rotation of the door onits fulcrum and an opening of the doorway to re lieve the pressure- Inthis manner, the: doorway is opened only to the extent necessary forrelief and: closed again by the weight of the counterweight porti'on.

In the event of a sudden explosive thrust, the door is fully rotatedwith the "counter-weight portion striking the interior of the shield".inst above. the. doorway-. With. the pressure relieved fromtheinterior'of the heating unit, thecounter weigh-t portion reboundsbackwardly to: move and maintain the coveringportion over the doorway;By this construction, the doorway is automatically opened and. closedtoregulate the venting of pressure from the heating unit.

It is,, therefore, an important object of this invention toprovide anautomatic pressure vent for. the interior of a heating unit.

Another object of this invention is the provision in aheating unit of avent which relieves internal pressure therefrom and automaticallyclosesvwhen the'pressure is relieved.

A still further object of this invention is the provision in a heatingunitof a rotatable door normally maintained in a closed position by acounter-weight.

Yetanother object of this invention. is the provision of a doordisconnectedly mounted in a doorway for swinging movement therein.

Qther and further objects of the invention will become. apparent tothose skilled in. the art from the: following detailed description ofthe. preferred embodiment of the invention as disclosed intheaccompanying, drawing, in which:

Figure l is a fragmentary view of a portion oi. a. heating unit.illustrating the applied shield and pressurerrelief door of thisinvention;

Figure 2. is a cross-sectional view, with parts in elevation, takenalong a vertical plane through the center of the construction shown inFigure 1.: and,

Figure. 3 isuan. enlarged rear view in. elevation 01 the. door;construction illustrated in section in Figurez.

It is. intended that the pressure relief device of this invention. be.applied to a, heating unit such as afurnace, 'boiler or the. llike.However, from the. following description it. will be apparcut that the.device may be applicable toany construction in which. internal pressuresare to be relieved. and, after relief. to again seal the interiorthereof In Figure. 1,. there. is illustrated a portion. of a, sidewallor face ID. of a heating unit havin a doorway H; from which the.customary door has been removed. In place of the door is provided acoveringshield 12-... This shield may be of onepiece. construction.However, as shown it comprises an upper section l3. and a. lower sectionIA, The lower section M is of the inverted U-shape construction theupper portion of which is connected by rivets l5, [.5 or the like; to:the rear face-of the lower portionof thev upper section l3. Both of thedownwardly extending legs of the lower section are offset forwardly toenage the face of the heating unit at the sides and below the doorway.The opening between the legs is sized to receive therethrough a burnerdevice l6 which rests on a ledge ll, either as the bottom of the doorwayor provided as an inward extension thereof. This two-piece constructioneffects greater strength and ease in varying the burner mechanismopening by replacing only the lower section.

A doorway H3, in the upper portion of the shield section [3, receivestherein a door l9. As best shown in Figures 2 and 3, the door 19 has adoorway covering portion 20 and an inwardly offset counter-weightportion 2!. The counterweight portion includes a downwardly extendingleg Zia and an angularly upward extending leg 2Ib forming a V-shape.Joining the doorway covering portion 20 and the downwardly extending leg2| a is an offset fulcrum 22 the bottom surface of which is arranged tofreely rest on the lower edge of the doorway opening H3.

The legs of the counter-weight portion, being positioned below thefulcrum of the door, rock the door on its fulcrum to a position in whichthe portion 20 normally covers the doorway opening. It will be observedthat both the fulcrum and the counterweight portion are narrower inwidth than either the doorway or the doorway covering portion. Thisarrangement permits ease of assembly by merely inserting thecounter-weight portion through the doorway until the fulcrum rests onthe bottom edge thereof. The doorway is thereby closed as shown inFigure 2.

When a pressure builds up within the interior of the heating unit andexerts a thrust against the inner face of the doorway covering portion20 sufiicien-t to overcome the weight of the counter-weight portion, thedoor rotates on its fulcrum to vent the pressure to the exterior. Shouldthe pressure build up suddenly as by an explosion, the thrust exertedagainst the door forces it to a position illustrated by dotted lines inFigure 2. In this position the doorway is entirely opened until the endof the leg 2 ib strikes the shield just above the doorway It. The legsZia and 2!?) so extend from the fulcrum 22 that the space between thefree end of leg 2m and the fulcrum is greater than the height of thedoorway thereby insuring the striking of the shield by thecounter-weight portion and limiting the rocking of the covering portionaway from the doorway. Venting is still possible between the sides ofthe narrower counter-weight portion and the sides of the doorway whenthe door has been moved to a fully open position.

The force of striking the shield effects a rebounding of thecounter-weight portion and a closing of the doorway. To the degree thatthe counter-weight portion is effective will depend the opening of thedoorway for venting of the interior of the heating unit.

It will be observed that the shield is so constructed as to be rotated180 should it be desirable to place the burner unit above the ventingdoorway. Although no fastening means are shown for attaching the shieldto the heating unit any of the well-known means may be employed, such asrivets, bolts, or the like.

The invention has been described herein more or less precisely as todetails, yet it is to be understood that the invention is not to belimited thereby, as changes may be made in the arrangement andproportion of parts, and equivalents may be substituted, withoutdeparting from the spirit and scope of the invention.

The invention is claimed as follows:

1. In a heating unit having a doorway, a closure member for said doorwaycomprising a door portion, a counterweight portion normally extendingbelow and away from said door portion, and an intermediate ofisetconnecting said portions and being arranged to rest and fulcrum on anedge of the doorway to position said portions on opposite sides thereof,the door portion being rockable on said offset to positions covering anduncovering said doorway, and said counterweight portion normallymaintaining said door portion in covering position and being narrower inwidth than the doorway for insertion therethrough with its free endbeing spaced from the fulcrum at a distance greater than the height ofthe doorway thereby limiting movement of the door portion away from thedoorway.

2. In a heating unit having a doorway, a closure member for said doorwaycomprising a door portion, a counterweight portion having one legnormally extending below said door portion and another leg extendingupwardly and away from said one leg, and an intermediate offsetconnecting said portions and being arranged to rest and fulcrum on anedge of the doorway to position said portions on opposite sides of thedoorway, the door portion being rockable on said offset to positionscovering and uncovering said doorway, and said counterweight portionnormally main taining said door portion in covering position with thefree end of said another leg being spaced from the fulcrum at a distancegreater than the height of the doorway whereby to strike the top of thedoorway when the closure member is rocked on the fulcrum to limitmovement of the door portion in an uncovering direction.

3. In a heating unit having a doorway, a 010- sure member for saiddoorway comprising a door portion, a counterweight leg extending inopposed parallel relation to said door portion, an offset fulcrumconnecting said door and leg, and another leg on said counterweightextending angularly upward from the first leg and terminating at adistance from the fulcrum greater than the height of the doorway, saidfulcrum being arranged to rest on the lower edge of the doorway toposition the door and counterweight on opposite sides of the doorway,said counterweight normally maintaining the door portion in coveringposition over the doorway and when the closure member is rocked on thefulcrum away from the doorway the end of said another leg striking thetop of the doorway to limit movement of the door portion in anuncovering direction.

WILLIAM P. AYERS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 123,252 Eldridge Jan. 30, 1872518,624 Olsen Apr. 24, 1894 1,574,711 Steele Feb; '23, 1926 1,783,418Field Dec. 2, 1930 2,004,948 Irsch June 18, 1930 2,160,262 Engles May30, 1939 2,193,274 Eckman Mar. 12, 1940

